Convalescent plasma therapy holds promise as a transient treatment for COVID-19. Yet, blood products are important sources of HIV infection in low- and middle-income nations. Great care must be taken to prevent plasma therapy from fueling HIV epidemics in the developing world.
The COVID-19 pandemic has inspired rapid research towards medications and vaccines to prevent the spread of the disease. Many drugs have been promoted as potential treatments for the disease, including hydroxychloroquine, azithromycin, Remdesivir, Avifavir, ivermectin, chlorine dioxide, among others1. Their effectiveness has been based on small studies and massively inflated by the media, only to later show limited to no benefit in larger studies and, sometimes, even cause severe side effects. The reality is that, to date, there is no proven drug to treat COVID-19. A potential vaccine will take at least 1 year to be developed and tested. Yet, a promising strategy to hold down the fort has arisen: convalescent plasma therapy. Trials to treat COVID-19 using this method are being initiated in many countries, including low- and middle-income nations in Africa, Southeast Asia, and Latin America.
Convalescent plasma therapy is based on the concept of passive immunity. Individuals who recover from SARS-CoV-2 infection have, in principle, developed neutralizing antibodies against the virus2. Collecting plasma, the liquid component of blood, from someone who has recently recovered from COVID-19 and infusing it into someone with an ongoing infection would confer the plasma recipient with antibodies to combat the virus3. Of note, this is an immediate transient treatment and does not replace the long-lasting immune memory generated by a vaccine. Indeed, high-affinity IgG antibodies have a half-life of up to three weeks in blood4. Nevertheless, the hope is that the infusion of convalescent plasma enriched in antibodies will substantially boost the recipient’s immediate immune response to clear the virus.
The infrastructure for collecting and administering plasma exists. The risks are known and rather low when the healthcare infrastructure is optimal. More than 16,000 patients at hundreds of US hospitals have received convalescent plasma therapy for COVID-19. A study in New York City found that convalescent plasma recipients had improved survival and less-supplemental oxygen requirements than control patients3. Yet, convalescent plasma therapy is not without its perils, especially in low- and middle-income nations with suboptimal healthcare infrastructures and less strict regulations. Blood transfusions can transmit blood-borne pathogens5 and lead to conditions such as transfusion-related acute lung injury and transfusion-associated circulatory overload6. In fact, blood transfusions have been shown to represent an important source of HIV infection in many low- and middle-income countries, being associated with positive HIV status7. It is unlikely that most low- and middle-income countries will be able to secure the blood supply by universal HIV testing7. Even when funding is provided, access to medical materials and supplies in the international market remains difficult for the developing world8.