Which countries are considering booster vaccines for covid-19?

Editor’s note (August 5th 2021): this story was updated to include the World Health Organisation's plea for a moratorium on booster shots

THE RACE TO vaccinate the world is not a fair one. Even as some countries struggle to get first doses out into the arms of their most vulnerable, countries with advanced vaccination campaigns are starting to consider giving “booster” shots. On August 4th the World Health Organisation (WHO) called on countries to halt the distribution of extra shots for at least two months to allow supplies to go to those most in need. Which countries are planning boosters, and why?

Vaccines work by exposing the body to a harmless form of a pathogen, so that the immune system can create defences against the disease. This immune memory means that the body knows how to respond when it encounters the virus in the future. Although there has been much angst about waning levels of antibodies in those who have received vaccines, such a drop is to be expected. When someone is infected with the virus, the immune system will spring into life and antibodies will be churned out in order to fight the active viral infection. Five of the six covid-19 vaccines so far approved by the WHO require two doses spaced several months apart. However, a third dose of vaccine, whether it is the same vaccine or a different one, is known to offer a short-term boost of immunity.

Israel began giving extra shots of the Pfizer/BioNTech jab to over-60s this week and intends to have 1m vaccinated by the end of August. France has decided to offer boosters from September to 1.7m people in care homes, those over 75 and those who have health conditions that make them vulnerable. Germany has similar criteria. These groups are most vulnerable to infection with covid-19, and some governments seem to have decided that it is worth offering additional protection. Britain has not decided whether it will distribute boosters but has warned the health service that it should be prepared to do so in September if they are needed. China is thinking in a similar way but does not think the general population will need boosters within a year of vaccination. Nonetheless, some countries that relied on two Chinese vaccines have concerns about the drugs’ efficacy so want to offer an extra shot of something else. Bahrain and the United Arab Emirates will offer a shot of Pfizer to those citizens who had Sinopharm while Indonesia plans to give health-care workers who were previously given two doses of Sinovac an extra one of Moderna.

The emergence of the Delta variant, which is spreading rapidly and is even being found among the fully vaccinated, has accelerated the debate. Although drug firms are researching vaccines that may fight individual variants, something that might be offered as a booster, these have not yet proven necessary. Current vaccines are protecting well against severe disease and hospitalisation of patients with Alpha and Delta, even though they were designed to deal with the original strain. That is why many health authorities, including those in America and the European Union remain cool on the idea of giving third doses. The WHO says it has not yet seen evidence to prove the need for a third shot. These views may shift over time, as more evidence accumulates on individuals who are not well protected by the existing regimens.

Selling boosters, though, is great business. Pfizer and Moderna have both announced that third doses of their vaccines would be needed and are lobbying governments for authorisation to do so. They have also recently increased the prices of their products. On the back of projected vaccine sales Pfizer raised its 2021 revenue forecast at the end of July, to $33.5bn. But demand for first and second doses is still so high that in many parts of the world the discussion about booster jabs is being watched with horror. As the WHO's plea highlights, a third dose to an individual in a rich country could mean a longer wait for someone in a poor country to get theirs first. Many believe that the global priority is to deliver first jabs, not third.