Now that the saner populations of the world are reaching a critical mass of  vaccination against COVID, our attention must turn to whether booster vaccinations are necessary. And as with everything emerging about COVID, it is a rapidly changing picture.

Choose a different vaccine to boost and only one dose

Eleven years ago, US Infectious Disease Guru Anthony Fauci, when discussing a similar global viral threat, the influenza pandemic, was very clear about the need to develop new and different vaccines to help stimulate our immune systems. Not boosters of the same ones. 

Sure, additional booster doses might be necessary to extend the duration of our protection against COVID and we really do not know whether primary series and booster doses can or should be different. It is also unclear WHEN, NOT WHETHER previously infected persons would benefit from vaccination and with what vaccine. 

The success of the vaccines is their commercial downfall in marketing booster doses. Approved COVID-19 vaccines have high efficacy and so there will always be too few ‘vaccinated infected’ people to assess whether a booster of the same or similar vaccine will extend the protection – despite how much the vaccine manufacturers, who have large investments in the current vaccines, attest to further protection (usually by using animal models).

We can only follow our previous pandemic models and vaccinations. In this case, the nearest analogue is the influenza vaccination programme. Revaccinating with the same strains of influenza vaccine was jettisoned years ago.  It was recognized early on that initial exposure to an influenza virus affects the body’s immunologic response. The “original antigenic sin,”  OAS as it was called, meant that infections and vaccinations can imprint a response to subsequent influenza infections and potentially to influenza vaccinations. Additionally, imprinting is likely to affect how individuals respond to different universal vaccine antigens.

OAS can trigger our immune systems to evade emerging variants in those who had been infected by or vaccinated against earlier variants. In the context of COVID, we have very little evidence about whether this will occur in humans.

Whatever the responses, they will be highly individualistic. 

With 8 billion people to vaccinate with two-dose regimens, it is estimated that we need 10–11 billion doses globally to interrupt transmission. At an estimated global vaccine manufacturing capacity of 2–4 billion doses annually, it will be 2023–2024 before enough vaccine can be manufactured.

For those of us who want to protect ourselves first and put the welfare of others second, if at all, at least choose a different vaccine to boost – and only one dose.

The advice to use the same vaccines as boosters, first in immunocompromised populations is as confused as the advice about masking. We must urge the sleeping giant WHO, Dr. Fauci and other vaccine researchers to develop a simple production strategy and yearly vaccination plan as was done for influenza.