November 16, 2023

Division of STD Prevention
Centers for Disease Control and Prevention
1600 Clifton Road NE
Mailstop US12–2
Atlanta, GA 30329
Attn: Docket No. CDC–2023–0080

RE: Guidelines for the Use of Doxycycline Post-Exposure Prophylaxis for Bacterial Sexually Transmitted Infection (STI) Prevention; Request for Comment and Informational Presentation

Dear Dr. Leandro Mena:

I am submitting the following comments on behalf of the R Street Institute (R Street), a nonprofit, nonpartisan public policy think tank based in Washington, D.C. R Street’s Integrated Harm Reduction department is committed to promoting harm reduction methods, including those focused on sexual health.

In light of a troubling increase in bacterial sexually transmitted infections (STIs), there is a profound need for new methods that can prevent these infections.[1] Although condoms, a tried and true harm reduction tool, are one way to prevent STIs, not every person chooses to use them during every sexual encounter. Pharmaceuticals for the prevention of some STIs, like HIV, with pre-exposure prophylaxis (PrEP) has been a revolution. Recent research indicates that post-exposure prophylaxis with doxycycline (doxy-PEP) can prevent STIs in specific populations.[2] Now that the Centers for Disease Control and Prevention (CDC) has proposed guidelines for doxy-PEP, medical providers have a new harm reduction tool to decrease STI incidence.

I. Evidence supports the proposed guidelines for doxy-PEP use

Considering the existing body of evidence, the proposed guidelines for doxy-PEP use are appropriate. Given the inclusion criteria for the clinical trials, it is reasonable to suggest limiting doxy-PEP use to “gay, bisexual, and other men who have sex with men, and for transgender women, with a history of at least one bacterial STI (i.e. gonorrhea, chlamydia or syphilis) in the last 12 months.”[3] Additionally, medical providers should be encouraged to engage in a collaborative assessment of risk and reasons for using doxy-PEP with their patients. This would leave more room for provider discretion and patient-centered practice.

II. Consider clarifying eligible populations and appropriate use

Although the language of the guidelines is largely clear, there is some room to clarify the eligible populations. The guidelines currently read, “Doxycycline 200mg taken once orally within 72 hours of oral, vaginal or anal sex should be considered for gay, bisexual, and other men who have sex with men, and for transgender women…”[4] It might be clearer to simplify the list of sexual/gender identities to “Doxycycline 200mg taken once orally within 72 hours of oral, vaginal or anal sex should be considered for all men who have sex with men and transgender women with a history…”

It is possible that some people would interpret the statement as including gay and bisexual women because there is no mention of gender until the end of the list. Simplifying the recommendation to “all men who have sex with men and transgender women,” limits the possibility of someone defining “gay” or “bisexual” more broadly than intended. Although misinterpretation of the current language may be unlikely, considering alternative language may be beneficial.

Additionally, it would be helpful to clarify the proper use of doxy-PEP. The prescribing recommendations are as follows: “the recommended dose is 200 [milligrams] once as soon as possible within 72 hours after having oral, vaginal or anal sex with a maximum dose of 200mg every 24 hours.”[5] The maximum dose is not clear from the proposed recommendations. “Doxycycline 200mg taken once orally within 72 hours…” could be interpreted as meaning doxycycline should be taken only once in a 72-hour period or once for every sexual encounter. Based on the clinical trial protocols, medical practitioners should encourage patients to try to take doxycycline within 24 hours of a sexual encounter.[6] It is important to ensure that the maximum dose and ideal use is communicated clearly to medical providers and their patients to minimize the risk of using more doxycycline than necessary or dosing improperly.

III. The proposed guidelines will decrease the incidence of bacterial STIs

Providing people with another form of highly effective harm reduction for sexual health will certainly prevent cases of bacterial STIs. As with any intervention, uptake and adherence will determine the magnitude of the decrease in bacterial STIs. Although it is possible that there will eventually be a population-level effect from implementing doxy-PEP, it may take time to appear. Even if there ends up being no statistically significant change in population-level rates of bacterial STIs, improving individuals’ health through prevention is a sufficiently good reason to publish guidance for providers to follow.

Evaluating the outcome of the guidelines based on population-level trends may not capture the benefits to individuals. For example, few would argue that expanding PrEP use is not beneficial. Nevertheless, evidence of decreased rates of HIV transmission at the population level is still limited.[7] Still, many people have benefited from wide availability of PrEP.

IV. Reaching populations that can benefit from doxy-PEP and planning for the future

Ensuring that eligible populations receive doxy-PEP prescriptions is vital to the success of the intervention. Starting with people who are engaged in care and have existing PrEP prescriptions is one way to raise awareness in a community of people who already accept the use of medication to prevent STIs.[8] Nevertheless, due to the uneven uptake of PrEP across demographic groups, this strategy will reach only a minority of the eligible population.[9]

Engaging community partners (such as harm reduction organizations) and health care providers will also be key to reaching populations that can benefit from doxy-PEP. Creating separate educational materials for providers, community partners and the public will enable individuals to understand the guidelines for doxy-PEP and provide an opportunity to dispel any anticipated concerns for each group. Educating harm reduction organization staff may be a way to target people who are eligible for doxy-PEP but less engaged with the traditional health care system.

Distrust of the medical establishment may also be a barrier to doxy-PEP uptake among some eligible individuals, especially minority communities.[10] Some studies have shown that distrust of the medical establishment decreases willingness to use, adherence to, awareness of and current use of PrEP.[11] In case similar concerns may be a barrier to doxy-PEP use, emphasizing that the use of doxy-PEP is as-needed and does not require taking a medication daily may help people who are less trusting of the medical establishment feel more comfortable using doxy-PEP.

Although doxy-PEP is currently only being recommended for men who have sex with men and transgender women, if there is a possibility of expanding this recommendation at a later time, doxy-PEP should be promoted thoughtfully. Take some of the challenges with promoting PrEP to broader swaths of the population as an example. PrEP, although now recommended for anyone at risk of contracting HIV through sex, has been largely associated with and marketed to men who have sex with men.[12] This continues to contribute to misunderstandings among other groups who could benefit from PrEP about their eligibility for the medication.[13] Ensuring that early marketing and branding of doxy-PEP does not lead to future confusion about availability may be something to consider when building public education campaigns. In the more immediate term, narrow marketing based mainly on demographics may discourage men who have sex with men who may not identify as gay or bisexual from considering the intervention due to perceived stigma.[14] Similarly, education and marketing campaigns should be non-judgmental and include people from diverse populations, which may help uptake across all ages, races and ethnicities.[15]

V. Conclusion

There are many things to consider when implementing a new public health intervention. From identifying target populations to developing educational materials, it is imperative to approach each task with an eye toward evidence and inclusivity. The doxy-PEP guidelines are evidence-based and can reach many at-risk populations if promoted appropriately. Thank you for the opportunity to comment on these guidelines and your consideration of this feedback.

Respectfully submitted,

Chelsea Boyd, MS
Integrated Harm Reduction Research Fellow

R Street Institute
1411 K Street NW
Suite 900
Washington, D.C. 20005
[email protected] 

[1] Centers for Disease Control and Prevention, “Infections continue to forge ahead, compromising the nation’s health,” U.S. Department of Health and Human Services, April 11, 2023.

[2] Centers for Disease Control and Prevention, “Supplemental material: Guidelines for the Use of Doxycycline Post-Exposure Prophylaxis for Bacterial Sexually Transmitted Infection (STI) Prevention,” U.S. Department of Health and Human Services, Oct. 2, 2023.

[3] Ibid.

[4] Ibid.

[5] Ibid.

[6] Anna F. Luetkemeyer et al., “Postexposure Doxycycline to Prevent Bacterial Sexually Transmitted Infections,” The New England Journal of Medicine 388 (April 6, 2023) pp. 1296-1306.

[7] Dawn K. Smith et al., “Evidence of an Association of Increases in Pre-exposure Prophylaxis Coverage With Decreases in Human Immunodeficiency Virus Diagnosis Rates in the United States, 2012–2016,” Clinical Infectious Diseases 71:12 (Dec. 15, 2020), pp. 3144–3151.; Julia L. Marcus et al., “Has Pre-exposure Prophylaxis Made a Difference at a Population Level? Jury Is Still Out,” Clinical Infectious Diseases 71:12 (Dec. 15, 2020), pp. 3152–3153.

[8] Jenell Stewart and Jared M. Baeten, “HIV pre-exposure prophylaxis and sexually transmitted infections: intersection and opportunity,” Nature Reviews Urology 19 (2022), pp. 7-15.

[9] Centers for Disease Control and Prevention, “PrEP for HIV Prevention in the U.S.,” U.S. Department of Health and Human Services, Sept. 29, 2023.

[10] Martha Hostetter and Sarah Klein, “Understanding and Ameliorating Medical Mistrust Among Black Americans,” The Commonwealth Fund, Jan. 14, 2021.; Devon Kimball et al., “Medical Mistrust and the PrEP Cascade among Latino Sexual Minority Men,” AIDS Behavior 24:12 (Dec. 1, 2021), pp. 3456-3461.

[11] Kimball et al.; Sean Cahill et al., “Stigma, medical mistrust, and perceived racism may affect PrEP awareness and uptake in black compared to white gay and bisexual men in Jackson, Mississippi and Boston, Massachusetts,” AIDS Care 29:11 (November 2017) pp. 1351-1358.

[12] Centers for Disease Control and Prevention, “How Do I Prescribe PrEP?”, U.S. Department of Health and Human Services, Oct. 5, 2023.; Rasheeta Chandler et al., “The pre-exposure prophylaxis (PrEP) consciousness of black college women and the perceived hesitancy of public health institutions to curtail HIV in black women,” BMC Public Health 20 (July 28, 2020).

[13] Ibid.

[14] Jaime Martinez and Sybil G. Hosek, “An exploration of the down-low identity: nongay-identified young African-American men who have sex with men.,” Journal of the National Medical Association 97:8 (August 2005), pp. 1103-1112.; Karolynn Siegel et al., “Sexual behaviors of non-gay identified non-disclosing men who have sex with men and women.,” Archives of Sexual Behavior 37:5 (2008), pp. 720–735.

[15] Brooke G. Rogers et al., “Intervention Messaging About Pre-Exposure Prophylaxis Use Among Young, Black Sexual Minority Men,” AIDS Patient Care and STDs 33:11 (Nov. 5, 2019).; Lance C. Keene et al., “#PrEP4Love: success and stigma following release of the first sex-positive PrEP public health campaign,” Culture, Health & Sexuality 23:3 (March 26, 2020), pp. 397-413.