Vaccines help in activating the immune system and in some immunocompromised patients, this ability can be impaired, so a third dose may help in boosting the immunity response. However, there are several questions that come along with the third recommended COVID-19 dose, especially, whether it is really necessary.

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Third dose of COVID-19 vaccination for immunocompromised individuals– need of the hour

The FDA modified the emergency use authorisations (EUAs) for Pfizer and Moderna's COVID-19 vaccines to include an extra booster dosage for select immunocompromised individuals after weeks of speculation. Solid-organ transplant patients and those with diseases "thought to have a comparable degree of immunocompromise" who had previously received one of the two mRNA vaccinations are among these people. The FDA updated the Pfizer-BioNTech and Moderna messenger RNA vaccines' emergency use authorisation to allow a third dose "in certain immunocompromised individuals, specifically solid organ transplant recipients or those diagnosed with conditions that are considered to have an equivalent level of immunocompromise."

Third doses of the same vaccination should be given at least 28 days following the second dosage to eligible patients aged 18 years or older for the Moderna vaccine and 12 years or older for the Pfizer-BioNTech vaccine, according to the FDA.

The Johnson & Johnson vaccination is excluded from the authorisation. The Advisory Committee on Immunisation Practices of the Centers for Disease Control and Prevention voted 11-0 to recommend a third dose of the two vaccinations for patients who are moderately or severely immunocompromised.

According to the ACIP workgroup that examined and recommended the intervention, the "beneficial effects" of adding a third dosage "clearly exceed the adverse repercussions in the majority of situations." A caveat, according to an FDA official, is that a third dosage has been found to be only modestly beneficial at improving protection against COVID-19.

The backdrop of the new recommendation 

Clinicians and patients alike applaud the FDA's approval of a third vaccination dosage of the Pfizer or Moderna vaccine for immunocompromised individuals. Giving these patients a third dose of vaccination is consistent with what has been done in other nations like France, Germany, and Israel, for example, have all previously administered third doses to immunocompromised individuals. While the majority of hospitalised cases in the United States and elsewhere have been among the unvaccinated, transplant recipients and other immunocompromised individuals have a lesser probability of responding to vaccines as measured by antibody response and, more notably, have been hospitalised with significant breakthrough illnesses.

Numerous small observational studies have previously shown that transplant recipients may potentially gain from a third injection owing to the increased likelihood of an antibody response. Additionally, a recent modest Canadian placebo-controlled randomised controlled trial demonstrating the efficacy of the third dosage in transplant patients provides additional credence that this is the correct approach. Ideally, bigger randomised controlled trials that report clinical outcomes such as symptomatic illness, hospitalisations, and fatalities avoided are preferred. However, in the midst of a rapidly spreading pandemic and a delta surge at the moment, time is critical.

Everything brings its own element of unanswered questions. Who is considered immunocompromised? For how long? Even after the third dosage, will protection continue in this population? What if a patient's response to a third dosage is insufficient? Will there be a fourth or a fifth? While recommending an extra vaccination dosage in this group is a positive step, we will need to establish and then improve eligibility criteria for the broad range of prospective patients with a certain level of immunological impairment.

Disclaimer- The views and opinions expressed in this article are those of the author's and do not necessarily reflect the official policy or position of M3 India.

The author is a practising super specialist from New Delhi.