Table 1.

Example mWACh^a-PrEP^b SMS text messages based on the IMB^c model.

Construct		Week	Example messages
Information
	Dosage	2 weeks after PrEP initiation	{name}, this is {nurse} from {clinic}. There are some misconceptions about PrEP in the community. People should not only take the PrEP pill just before potential exposure to HIV. Rather, it should be taken every single day for it to build up in your system and offer protection against HIV. Is there anything else that you have heard about PrEP in the community?
	Side effects	2 weeks after PrEP initiation	{name}, this is {nurse} from {clinic}. A few PrEP users may experience side effects related to PrEP. Most side effects lessen after the first few weeks of use once the body is used to the medication. Please let us know if you are having any side effects. We can help you manage them or know if it is okay to continue.
	Safety	19 weeks after PrEP initiation	{name}, this is {nurse} from {clinic}. PrEP is very safe and one of the ways you can protect yourself from HIV. With this pill, you can keep yourself safer from HIV. Are you still taking the medication? Do you have any questions or concerns?
	Use logistics	4 weeks postpartum	{name}, this is {nurse} from {clinic}. At this time, you may have a lot to deal with as you adjust to having a newborn. Remember to continue taking care of yourself to prevent HIV by consistently taking PrEP. Do you have any questions?
	Efficacy	1 week after PrEP initiation	{name}, this is {nurse} from {clinic}. PrEP is very effective at preventing you from getting HIV. For this effectiveness to be achieved, it is important to take the medication for the first 7 days after initiation without being exposed and thereafter daily. You can use condoms or abstain during this period. Do you have any concerns about PrEP?
Motivation
	Perceived benefits of adherence	4 weeks after PrEP initiation	{name}, this is {nurse} from {clinic}. PrEP is very effective at preventing you from getting HIV if you take it every day. It also helps prevent HIV in your baby if you are pregnant. If you miss too many doses it may not work. Are you having any challenges taking the medication?
	Risk perception	17 weeks after PrEP initiation	{name}, this is {nurse} from {clinic}. PrEP is used when you think you might be at risk of HIV. If you think you are no longer at risk, like if your partner tests and is negative or you are no longer with a partner, you can stop PrEP. Do you have any questions?
	Value of HIV Prevention	15 weeks after PrEP initiation	{name}, this is {nurse} from {clinic}. You are doing a great job taking care of yourself. Deciding to take PrEP is an important way to protect yourself from HIV. It is also important to be tested regularly. Do you have any questions about PrEP?
Behavioral Skills
	Discern seasons of high HIV risk	6 weeks after PrEP initiation	{name}, this is {nurse} from {clinic}. Some women choose to discontinue PrEP for many reasons. It is okay to stop the medication if you decide. We would want to know why people stop PrEP. Have you stopped taking PrEP? If you have why did you stop?
	Remember to take PrEP daily	8 weeks after PrEP initiation	{name}, this is {nurse} from {clinic}. It can be difficult to take medications every day especially if you are trying to be discrete. Many people ask a friend to help remind them, set a timer on their phone, or take it with a meal. You can also put it in a different container you can carry with you in private. How do you remember to take your medication? Do you have any challenges taking it every day?
	Manage PrEP use in relation to partner	9 weeks after PrEP initiation	{name}, this is {nurse} from {clinic}. PrEP enhances the power you have to make an independent decision regarding preventing yourself from HIV as you do not have to rely on your partner for this decision. Do you have any questions about PrEP?
Moderating Factors
	Psychological health	3 weeks after PrEP initiation	{name}, this is {nurse} from {clinic}. Sometimes new mothers can feel sad, anxious, or worried all the time. This happens to many women and can cause crying and difficulty sleeping. Are you having any of these problems?

^amWACh: Mobile Solutions for Women’s and Children’s Health.

^bPrEP: pre-exposure prophylaxis.

^cIMB: Information-Motivation-Behavioral Skills.