Impact of COVID-19 on vaccination programs: adverse or positive?

ABSTRACT

The COVID-19 pandemic has posed multiple substantial challenges, affecting not only public health but also economic systems, socio-cultural patterns, and political institutions. Studies have focused on the relationships between complex emergencies and natural disasters with outbreaks of infectious diseases. However, there is a dearth of relevant literature on the impact of a global pandemic on vaccination programs – an important topic because delays or stops in such programs are likely to result in outbreaks and epidemics of other infectious diseases. Thus, this article discusses the negative and positive impacts that the COVID-19 pandemic may exert on vaccination for vaccine-preventable diseases (VPDs). Negative impacts include the increased risk of VPD outbreaks in low-resource countries where vaccination programs must be temporarily halted to prevent the spread of infection. Positive effects include the strong possibility that the universally-recognized need for a coronavirus vaccine may increase people’s appreciation for vaccines in general, resulting in improved vaccination uptake once the pandemic passes. Concerned stakeholders, such as governments and the World Health Organization (WHO), should seize this moment to effectively build on these positive impacts by planning renewed and revitalized post-COVID vaccination programs.

Introduction

Infectious diseases have always constituted a major public health concern.¹ For their control and eradication, in 1974 the World Health Organization (WHO) launched an Expanded Program on Immunization (EPI) against six vaccine-preventable diseases (VPDs) – diphtheria (D), measles, pertussis (P), poliomyelitis (using Oral Poliovirus Vaccine [OPV]), tetanus (T), and tuberculosis (using the Bacillus Calmette-Guerin [BCG] vaccine).² Despite these unceasing and substantial efforts, only smallpox was eradicated while the remaining diseases are still affecting the worldwide population, in addition to other emerging infections.^3,4 Since then, new vaccines have been incorporated into the EPI. In 2013, 4.9 million deaths globally (9% of all deaths) were attributed to VPDs.⁵ In 2018, the global incidence rate for VPDs was 2.1 million,⁶ showing that progress was made, largely due to increased vaccine uptake. Nonetheless, VPDs still make a large contribution to the burden of disease, and several factors still result in vaccine refusal and low vaccination uptake. Numerous studies have illustrated these factors, which include anxiety about side-effects and suspicion and distrust of government-sponsored vaccination programs. These vary by country and are deeply related to socio-cultural, economic, political, and historical factors.^7–21

Various studies have explored the relationships among outbreaks, complex emergencies, and natural disasters.^22–28 Studies have also focused on other issues such as vaccine stock maintenance, operational costs, vaccination data quality, electronic registers, health information systems, parental reminder systems, and global positioning systems to monitor vaccinators.^19,29–34 One study gauged the timelines of childhood vaccination by using routine data to measure vaccination practices, and argued that delay in receiving scheduled vaccines left children vulnerable to these infectious diseases.³⁵ Nevertheless, there is a dearth of literature about how a global pandemic may affect vaccination programs for VPDs.

COVID-19 in historical context

In the past 100 years, there has been no other global pandemic at such a massive scale. The last such pandemic, the Spanish Flu, occurred in 1918 and infected 1/5th of the world’s population within months.³⁶ There remains a prominent contradiction about the aggregate of deaths from this deadly disease: estimates range from 20 to 50 or 100 million.^37–39 In more recent times, there have been other flu-related outbreaks, but they were less challenging, as were the coronavirus (CoV)-related Severe Acute Respiratory Syndrome (SARS) in China and the Middle East Respiratory Syndrome (MERS) outbreaks in China and Saudi Arabia, respectively.^40–44

The current ongoing COVID-19 is the third infection of CoVs among humans, and the first global pandemic in a century. After emerging in December 2019 – when a series of undetermined “pneumonia” cases were reported in Wuhan, in Hubei Province of China – it rapidly escalated around the globe.^45,46 COVID-19 has not merely challenged healthcare systems, but also economic systems, socio-cultural patterns, and political institutions. Although it may wind down, its effects will be long-lasting and will continue to present critical challenges. This pandemic has made people much more acutely aware of the challenges a microorganism can pose; hence, they are hoping that researchers can develop effective medication and, most importantly, a vaccine. In this article, I illustrate how the ongoing uncertainties about when the pandemic will end and whether or not an effective vaccine can be developed may affect the existing vaccination programs for VPDs. Briefly, these concerns may impact EPIs in two primary ways: adverse and positive.

Potential adverse impacts of COVID-19 on vaccination programs

Outbreaks of infectious diseases have been associated with complex emergencies and natural disasters,^22–24 such as floods, tropical cyclones (e.g., hurricanes and typhoons), tsunamis, earthquakes, and tornadoes.^25,26 Underlying reasons include large-scale population displacement and crowding, poor sanitation, lack of clean water, malnutrition, and low healthcare and vaccine coverage, leading to long-term deprivation of primary health care.^22,27,28

COVID-19 is not associated with natural disasters, yet some of its adverse impacts are similar, while others differ. Almost the entire world is currently observing social isolation, physical distancing, and quarantine either by choice or by force. Numerous countries have imposed lockdowns and curfews, while others have been more lenient in their responses. Both approaches have some logic behind them. In any case, it is clear that vaccination programs to control and eliminate other VPDs such as polio and measles are being significantly affected by the global response to COVID-19.

For this, there are three primary and interrelated reasons: (1) governments, global stakeholders such as WHO, and healthcare workers are currently primarily focused on dealing with the challenges posed by COVID-19; (2) routine vaccination programs in low-resource countries have been put on hold, as the vaccinators themselves may contract and/or transmit the virus;⁴⁷ (3) physical distancing and quarantine may mean that people will not be able to visit a healthcare facility to seek routine vaccinations for themselves or for their children.

In low-resource countries, newborns may not receive vaccines in a timely way, particularly the oral polio vaccine (OPV-0) and Bacillus Calmette–Guérin (BCG) at birth and the OPV 1, Penta 1, and Pneumococcal conjugate vaccine (PCV) 1 at the sixth week after birth. This delayed uptake of vaccination is less likely to occur for babies born in hospitals in high-income countries. However, babies in low-income countries who are more likely to be born in homes attended by traditional birth attendants (TBAs) or in small rural clinics may remain unvaccinated.

The most reasonable question to ask is, will it be possible for the overwhelmed and struggling healthcare systems across the world to continue to vaccinate newborns as well as older children? In addition, some babies may not get their scheduled vaccines – OPV II, Penta II, and PCV II, as well as OPV III, Penta III, and PCV III – during the 10th and 14th weeks, respectively. The Measles I and Measles II vaccinations for older children given during the 9th and 15th months are likely to also be affected. Pregnant women may miss the tetanus vaccination, which in some countries is already in a critical state.¹⁷ The current global pandemic may globally affect the WHO’s recommended 22 vaccines – of which some are area-specific (see Tables 1 and 2). ⁴⁸

Table 1.

Summary of WHO’s recommended routine immunizations for children^45.

				Interval Between Doses
Antigen		Age of 1st Dose	Doses in Primary Series	1st to 2nd	2nd to 3rd	3rd to 4th	Booster Dose	Considerations (see footnotes for details)
Recommendations for all children
BCG		As soon as possible after birth	1					Birth dose and HIV; Universal vs selective vaccination; Co-administration; Vaccination of older age groups; Pregnancy
Hepatitis B	Option 1	As soon as possible after birth (<24 h)	3	4 weeks (min) with DTPCV1	4 weeks (min) with DTPCV2			Premature and low birth weight Co-administration and combination vaccine High risk groups
	Option 2	As soon as possible after birth (<24 h)	4	4 weeks (min) with DTPCV1	4 weeks (min) with DTPCV2	4 weeks (min), with DTPCV3
Polio	bOPV + IPV	6 weeks (see footnote for birth dose)	4 (IPV dose to be given with bOPV dose from 14 weeks)	4 weeks (min) with DTPCV2	4 weeks (min) with DTPCV3			bOPV birth dose Transmission and importation risk criteria
	IPV/bOPV Sequentia	8 weeks (IPV 1st*)	1–2 IPV 2 bOPV	4–8 weeks	4–8 weeks	4–8 weeks
	IPV	8 weeks	3	4–8 weeks	4–8 weeks	See footnote
DTP-containing vaccine		6 weeks (min)	3	4 weeks (min) – 8 week	4 weeks (min) – 8 week	3 Boosters 12–23 months (DTP containing vaccine); 4–7 years (Td/DT containing vaccine), see footnotes; and 9–15 yrs (Td)		Delayed/interrupted schedule Combination vaccine; Maternal immunization
Haemophilus influenzae type b	Option 1	6 weeks (min) 59 months (max)	3	4 weeks (min) with DTPCV2	4 weeks (min) with DTPCV3	(see footnote)		Single dose if >12 months of age Not recommended for children > 5 yrs Delayed/interrupted schedule Co-administration and combination vaccine
	Option 2		2–3	8 weeks (min) if only 2 doses 4 weeks (min) if 3 doses	4 weeks (min) if 3 doses	At least 6 months (min) after last dose
Pneumococcal (Conjugate)	Option 1 3p+0	6 weeks (min)	3	4 weeks (min)	4 weeks			Schedule options Vaccine options HIV+ and preterm neonate booster
	Option 2 2p+1	6 weeks (min)	2	8 weeks (min)			9–18 months
Rotavirus		6 weeks (min) with DTP1	2 or 3 depending on product	4 weeks (min) with DTPCV2	For three dose series – 4 week (min) with DTPCV3			Vaccine Options Not recommended if >24 months old
Measles		9 or 12 months (6 months min, see footnote)	2	4 weeks (min) (see footnote)				Combination vaccine; HIV early vaccination; Pregnancy
Rubella		9 or 12 months with measles containing vaccine	1					Achieve and sustain 80% coverage Co-administration and combination vaccine; Pregnancy
HPV		As soon as possible from 9 years of age (females only)	2	6 months (min 5 months)				Target 9–14-year-old girls; Multi-age cohort vaccination; Pregnancy Older age ≥ 15 years 3 doses HIV and immunocompromised

Table 2.

Summary of WHO’s recommended routine immunizations for children.^45.

				Interval Between Doses
Antigen		Age of 1st Dose	Doses in Primary Series	1st to 2nd	2nd to 3rd	3rd to 4th	Booster Dose	Considerations (see footnotes for details)
Recommendations for children residing in certain regions
Japanese Encephalitis	Inactivated Vero cell-derived	6 months	2 generally	4 weeks (generally)				Vaccine options and manufacturer’s recommendations; Pregnancy; Immunocompromised
	Live Attenuated	8 months	1
	Live Recombinant	9 months	1
Yellow Fever		9–12 months with measles containing vaccine	1
Tick-Borne Encephalitis		≥ 1 yr FSME-Immun and Encepur ≥ 3 yrs TBE_Moscow and EnceVir	3	1–3 months FSME-Immun and Encepur 1–7 months TBE-Moscow and EnceVir	5–12 months FSME-Immun and Encepur 12 months TBE-Moscow and EnceVir		At least 1 every 3 years (see notes)	Definition of high-risk Vaccine options Timing of booster
Recommendations for children in some high-risk populations
Typhoid	TCV (Typbar)	>6 months	1					Definition High Risk; Vaccine options
	Vi PS	2 years (min)	1				Every 3 years	Definition of high risk
	Ty21a	Capsules 5 years (min) (see footnote)	3 or 4 (see footnote)	1 day	1 day	I day	Every 3–7 years	Definition of high risk
Cholera	Dukoral (WCrBS)	2 years (min)	3 (2–5 years) 2 (≥6 years)	≥ 7 days (min) < 6 weeks (ma	≥ 7 days (min) < 6 weeks (max)		Every 6 months Every 2 years	Minimum age Definition of high risk
	Shanchol, Defnition of high risk Euvchol and mORCVAX	1 year (min)	2	14 days			After 2 years
Meningococcal	MenA conjugate	9–18 months (5 µg)	1					Definition of high risk; Vaccine options; 2 doses if < 9 months with 8-week interval
	MenC conjugate	2–11 months	2	8 weeks			After 1 year	Definition of high risk; Vaccine options
		≥12 months	1
	Quadrivalent conjugate	9–23 months	2	12 weeks				Definition of high risk; Vaccine options
		≥2 years	1
Hepatitis A		1 year	At least 1					Level of endemicity; Vaccine options; Definition of high risk group
Rabies		As required	2	7 days			(see footnote)	PrEP vs PEP; Definition of high risk
Dengue (CYD-TDV)		9 years (min)	3	6 months	6 months			Pre-vaccination screening
Recommendations for children receiving vaccinations from immunization programmes with certain characteristics
Mumps		12–18 months with measles containing vaccine	2	1 month (min) to school entry				Coverage criteria > 80%; Combination vaccine
Seasonal influenza (inactivated tri- and qudri-valent)		6 months (min)	1 (≥ 9 years) 2 (<9 years)	4 weeks			Revaccinate annually: 1 dose only (see footnotes)	Priority risk groups, especially pregnant women Lower dosage for children 6–35 month
Varicella		12–18 months	1–2	4 weeks to 3 months per manufacturer recommendations				Achieve & sustain ≥ 80% coverage Pregnancy Co-admin with other live vaccines

Tables 1 and 2. Summary of WHO’s Recommended Routine Vaccinations for Children⁴⁸

Each day, according to the United Nations Children’s Fund (UNICEF), approximately 386,000 babies are born,⁴⁹ meaning that millions will be born during this pandemic who may not be able to appropriately receive the required OPV 0 and BCG vaccines. Other calculations about newborns based on a more extended period of COVID-19 show the potentially severe impacts. If the pandemic lasts longer than expected, then the aggregate of babies without required vaccination due to delays would substantially escalate. Although they may receive the vaccinations later, in the meantime, these unvaccinated babies will be more vulnerable to catching other infections.

Unvaccinated newborns are a severe public health concern, as are the older children who will receive delayed (or may miss completely) scheduled vaccinations. Those children, who are more likely than babies to catch and spread infections, are at much higher risk, especially against measles, Diptheria, and polio, particularly in countries where these viruses already prevail and vaccination rates are already low.

Despite global efforts such as the Measles and Rubella Initiative (MR&I), the measles virus still causes outbreaks worldwide. To name but a few, in 2012–13, two measles outbreaks occurred in Pakistan, mainly in Sindh province, and caused over 25,000 cases and 300 deaths.^50,51 In 2017, measles caused around 90,000 deaths worldwide,⁵² and in 2018, measles-related deaths increased to 110,000.⁵³ One year later, there was a 30% rise in measles cases across the globe.⁵⁴ During 2019, measles outbreaks occurred in the Philippines, killing around 30 people; in New York County, where the mayor declared an emergency; and in Switzerland, where two children died.^53,55

It is essential to mention that these measles outbreaks occurred when routine vaccinations, as well as supplementary immunization activities (SIAs), were being regularly conducted. Everything was “normal,” in that health care systems were not overwhelmed, and the vaccinators had no fears of infecting or being infected. During the current extremely challenging circumstances, measles outbreaks can be foreseen, because on 26th March 2020, WHO’s Strategic Advisory Group of Experts on Immunization (SAGE) recommended that all countries suspend mass vaccination drives against all VPDs, arguing that, “Any mass campaigns would go against the idea of social distancing.”⁵⁶ Suspensions of vaccination against measles in only 23 countries will result in 78 million unvaccinated children.⁵⁶ As vaccination programs cease in more countries, the aggregate of unvaccinated children will critically increase.

The longstanding Global Polio Eradication Initiative (GPEI) may also be severely affected. The wild poliovirus is still prevalent in Pakistan and Afghanistan. In Pakistan in 2019, there were around 150 polio cases, and as of April 2020, around 30 new cases have been reported.⁵⁷ By 24 March 2020, the GPEI had already directed countries to postpone their mass vaccination programs until the second half of this year: these campaigns reach around 400–450 million annually.⁵⁶ WHO’s Michel Zaffran – the head of GPEI – fears that the poliovirus will likely spread to polio-free countries.⁵⁶ Thus the United Nations is already expressing concern about the millions of children who will not receive vaccinations against measles, Diptheria, and polio, and who will then be at critical risk of infection.⁵⁸

To be clear about why the vaccination programs will be interrupted, the following are the central reasons: (1) These children, including their parents, are in social isolation, physical distancing or self-quarantine; many countries have imposed lockdown, curfews and put armies and police into action to push people to follow these rules; (2) healthcare systems are overwhelmed due to dealing with COVID-19; most healthcare personnel are actively engaged in the ongoing pandemic and even looking for volunteers; and (3) vaccinators who normally visit each door, especially during supplementary immunization activities (SIAs), cannot perform this task due to these reasons, including the fact that they themselves may be carriers of COVID-19 or vulnerable to catching it during vaccination. All these factors are complex, interlinked, and overlapping. Nevertheless, it is plausible that the pausing or stopping of routine vaccinations constitutes yet another foreseeable challenge that the COVID-19 pandemic is posing at a global level.

COVID-19’s potential positive impacts on vaccination programs

Vaccination programs in many countries have been subjected to political machinations, suspicions, rumors, and conspiracy theories.^59,60 For example, first Pakistan’s family planning program and then its vaccination program was locally coded as “Western plots” to sterilize Muslim women that serve supposed “hidden interests” of specific stakeholders.^11,18 This conspiracy theory, which is linked to geopolitics, resulted in suspicions, outright vaccine refusals, and the murders of some vaccinators.^11,15 In May 2011, a vaccination drive was used as a cover to locate and kill Osama bin Laden in Pakistan’s Abbottabad city; one Pakistani political analyst termed that event “vaccination suicide” due to its foreseeable implications on the vaccination program in the country.⁶¹ After that event, people’s perceptions of vaccination as a “plot” did indeed further strengthen, and assaults on vaccination teams increased significantly.^61–63 Likewise, in Cameroon, due to associating vaccination with colonization and corrupt governments, schoolgirls jumped from windows to run away from vaccinators.¹³ In Northern Nigeria, people suspected the quality of the vaccines and the intentions of the government.¹⁶

Nevertheless, COVID-19 has provided fertile ground for generating effective vaccination drives against all VPDs. The confounding factors that affect vaccine uptakes may now be significantly addressed and countered. Given the scale of COVID-19 and the universal desire for a vaccine against it, chances are higher that there may be a significant decrease in vaccine refusal, hesitancy, and anxiety. This longing for a vaccine that will protect people from the COVID-19 is highly likely to positively affect people’s perceptions about vaccination programs in general, making them more likely to accept other vaccines.

In this way, the COVID-19 pandemic has provided a valuable opportunity for the concerned stakeholders – e.g., governments and the WHO – who design and implement the EPI. Nonetheless, benefiting from this emerging opportunity substantially depends upon these stakeholders to formulate appropriate awareness programs to increase vaccine uptakes.

Conclusion

In sum, the COVID-19 pandemic has emerged as a greater global public health concern than any other phenomenon in living memory. This pandemic may have considerable effects on the efforts and programs concerning other VPDs chiefly in two ways, one negative and the other positive:

1. COVID-19’s negative effects include the halting of routine vaccination programs due to the rising need for resources to handle COVID-19 and to observe the required physical isolations and quarantines necessary for interrupting its transmission. Hence, millions of babies may receive delayed vaccines, such as OPV 0 and BCG, due at birth, especially those who will be delivered not in the hospitals of high-income countries but in the rural clinics or homes of low-income countries where viruses like poliomyelitis and measles are already prevalent. Vaccination uptake will also be substantially affected for older children, who may miss scheduled vaccinations due to quarantines as well as to the resources being thrown at stopping COVID-19. This unintentional lack of vaccination may cause outbreaks of other VPDs, consequently exerting further adverse impacts on COVID-19-affected economies and healthcare systems.

2. COVID-19’s positive effects on vaccination programs include the fact that the rapid spread of this virus may substantially affect people’s overall perceptions of vaccination due to their desire for a COVID-19 vaccine. This desire may result in increased awareness of the benefits of vaccination programs in general, ultimately resulting in a substantial increase in vaccination uptake. Therefore, once the need for social distancing is over, there will occur a prime moment for reinstituting and re-invigorating all vaccination programs; national and global stakeholders should take full advantage of this prime moment.

Practical suggestions: Carpe Diem!

The concerned stakeholders, such as governments and international organizations, should devise context-specific strategies to effectively seize this prime moment. Specifically, all the global, national and local level actors – such as GPEI, SAGE, national governments, provincial governments, district-level officials and local-level vaccinators – should equally and actively be engaged to undo the adverse consequences of the COVID-19 pandemic on vaccination and to benefit from its potential fertile grounds for overcoming doubts, suspicions, rumors and conspiracy theories regarding vaccination in general. In incorporating these qualitative aspects into vaccination programs, social scientists, mainly medical anthropologists, can play a pivotal role.

Furthermore, empirical studies are required to thoroughly investigate the relationship between low vaccination uptake during COVID-19 or similar emergencies and the rise of VPDs afterward. Also, studies should shift their focus of attention toward the impacts of the current pandemic on the entire healthcare system, including its implications for both chronic and infectious diseases.

Biography

Inayat Ali is a Ph.D. researcher in medical anthropology at the Department of Social and Cultural Anthropology, University of Vienna, Austria. His research has long focused on infectious diseases and vaccination programs in Sindh Province, Pakistan.

Disclosure of potential conflicts of interest

No potential conflicts of interest were disclosed.