The Covid-19 pandemic has caused immense suffering and loss. Combating the virus without hurting the economy is especially hard in Africa, where poverty and weak healthcare systems were already prevalent prior to the outbreak. Scientists and policymakers alike agree that a safe and effective vaccine is our best chance at fighting this pandemic. 

Africa should pay closer attention to human challenge trials (HCT) — one of the only ways to accelerate vaccine development without compromising safety. In these trials, consenting volunteers are given a vaccine candidate and then directly exposed to the coronavirus. To prevent community spread, they are kept in a secure biosafety facility for the duration of the trial. Deliberate exposure means challenge trials can test a vaccine more quickly than traditional phase three trials (the more common trials currently underway) where participants are not kept in a facility but rather return to their everyday routines to be exposed to the virus organically. 

HCTs are already garnering significant attention overseas with the UK government announcing that they will fund HCTs set to begin in January. It is troubling, however, to see the relatively little attention HCTs have received in the African context, since we stand to benefit the most from these trials as time is at least on our side.

The risks of directly exposing a volunteer to the virus are significant and should not be understated. Yet, studies have shown the risk of Covid-19 mortality for healthy people below the age of 34 (one in 25,000) to be less than other acts of public service, such as live kidney donation (one in 3,300) or even childbirth in the US (one in 6,600). 

When compared against the benefits of HCTs, these risks are entirely justified. 

The increased speed alone is of immense benefit during a pandemic in which lockdowns and restrictions are crippling small businesses and thrusting the population further into poverty. Another benefit of HCTs is the smaller number of volunteers needed for the study, meaning that volunteers can be closely monitored.

A final, general strength of HCTs is their robustness to lockdowns which significantly hinder phase three trials. If a country goes into lockdown (as the UK now has as at the beginning of November) the volunteers of phase three trials can no longer be organically exposed to the virus, delaying the trials’ conclusion. HCTs, however, are independent of lockdowns and restrictions and so are not hindered by these safety measures.

During a pandemic where the negative socioeconomic impacts are as concerning as the negative impacts on people’s health, we cannot afford delays in finding a vaccine. I believe this to be the reason for the necessity of HCTs: they balance the scientific and social considerations of finding a vaccine. They are rigorous and accurate due to the control of scientists at the trial facility, but also fast and robust to disruptions. 

Africa has strong reasons to support HCTs. While current phase three trials from companies like Moderna and AstraZeneca have shown very positive results, logistically it will take multiple vaccines from many different companies to vaccinate the entire world effectively. It is of no use to Africans if a vaccine is only available in First World countries, long before one is available in Africa. HCTs can be used to effectively and quickly compare vaccines, with the control vaccine replacing the placebo in the trial (and removing some of the risks to volunteers). Thus, if HCTs are used, the set of candidate vaccines can be narrowed down to only the effective vaccines which can then be produced and join the pool of available vaccines. 

Since Africa does not have necessary biocontainment facilities, it is unlikely that HCTs will be conducted on African soil in the near future. However, Africa can still make its voice heard on the global scene in media, science and international debates surrounding HCTs. African volunteers have already signalled their willingness to take part in challenge trials. Organisations such as 1Day Sooner offer Africans this opportunity to be heard. 1Day Sooner advocates on behalf of HCT volunteers and for the equal opportunity for all people to be vaccinated, including those from African countries. Without HCTs and advocacy organisations like 1Day Sooner, it will be significantly more difficult for African countries to maintain both a healthy population and a healthy economy.

Finally, the onus for African voices to be heard is not only on an individual basis but on a governmental one as well. The logistical issues around vaccinating African countries with foreign vaccines should be one of our government’s main concerns in this pandemic. Thus, it is time for the South African Department of Health and health departments from other African nations to endorse HCT and help facilitate their commencement in any way they can. 

It is time we take a more active role in finding the necessary, viable vaccines to end the pandemic — the lives of people across our continent depend on it. DM