Many wealthy countries have begun to offer additional coronavirus vaccines. Are these booster shots really necessary?
What evidence is there about booster shots?
It is not clear. Preliminary data suggests that people experience a decrease in their protective antibodies levels over the weeks and months following receiving their jabs. This is especially true for the highly infectious Delta variant. It is not clear what level of immune system armament or antibodies confer protective immunity.
It is important to know the amount of antibodies and other immune system soldiers required to protect against Covid-19. This is especially true for serious illness and death. Only after this level is measured and protection drops towards it, can booster vaccines be recommended.
Experts from the World Health Organization (WHO), have stated that there isn't enough scientific evidence to support additional shots. However, people who have certain underlying conditions, such as a weak immune system, may not respond well to the initial shots. In these cases, booster jabs might be justified, particularly against the Delta variant.
The Delta breakthrough cases are especially common in the over-60s. A booster dose reduces these effects. Danny Altmann, an immunologist at Imperial College London, stated that the same applies to immune-suppressed or vulnerable groups. It would be ideal to have targeted immune monitoring and boosting rooted within data.
According to Dr Simon Clarke (associate professor in cellular microbiology, University of Reading), the evidence supporting vaccine effectiveness against Delta supports booster jabs for vulnerable people.
Do different vaccines need to be used as booster jabs
The verdict is still out. The general consensus is that the jabs are presented to the immune system with the same target, but in slightly different ways, triggering a different immune response.
The UK currently offers two doses of the same jab. However, researchers are exploring the possibility of offering another dose of a Covid vaccine, or even a third dose. This could increase immunity. A preliminary study that looked at the effects of a third jab was published in June. It was based on Oxford/AstraZeneca shots containing a BioNTech booster and a Pfizer/Pfizer shot.
According to Matthew Snape (chief investigator and associate professor of paediatrics in vaccinology at Oxford), switching to an RNA vaccine may have some advantages in terms of antibody production based on the evidence.
There are some concerns about side effects from mixing and matching jabs. A study presented to the Joint Committee on Vaccination and Immunisation showed that side effects could be worse if people received a combination of jabs. This could have implications for using a booster jab.
What is the UK's approach to boosters
Sajid Javid (the health secretary) suggested last week that over-50s would be given a booster along with a flu jab. The programme is expected to start in September.
The JCVI, which advises government on vaccine policy has yet to give its final opinion on the booster program. Prof Adam Finn, a member of the JCVI, stated that on Thursday, the committee would decide which groups should receive a third shot.
He said that we need to concentrate on those who are more susceptible to getting sick again if they don't have a booster. However, he resisted the idea of routinely introducing third jabs. More evidence is needed before we can make a decision about a larger booster program.
It is highly unlikely that Covid booster vaccines will be offered in the UK starting in September. This is despite the concerns expressed by JCVI regarding the potential clinical benefits and wider risks to vaccine confidence. Sources close to JCVI have informed the Guardian.
What is the role of other countries?
Joe Biden, the US president, stated Wednesday that his administration would make Covid-19 vaccine boosters available to all Americans beginning on September 20th, in response to rising Delta infections. Israel is now giving vaccine boosters to people over 60, and the president Isaac Herzog has already received his.
Although the European Medicines Agency stated last month that there wasn't enough evidence to recommend boosters for certain groups, some countries decided to go ahead. France and Germany will begin to look at third doses of certain groups starting in September.
What's the reason for booster jabs being so controversial?
There is no clear evidence that booster shots are required for all fully vaccinated persons. However, there has been a moral argument against the administration of booster shots. Experts at WHO have stated that it is wrong to give them while many people are waiting for their first shots.
According to Dr Michael Ryan, director of WHO's emergency programme, we are going to give extra lifejackets out to people who have them, but were leaving others to drown in the water without one.
In a Guardian opinion piece, Seth Berkley, chief executive of Gavi (the Vaccine Alliance), and Andrew Pollard, director of Oxford Vaccine Group send a message to the rest of the world that large-scale boosting is needed in rich countries.
They said that this will cause many people to die as they will not have the chance to receive a single vaccine dose. We have two doses of vaccine time so we shouldn't rush to boost millions of people when there is no time. First doses first. It's as simple as that.
