Drive-through SARS-CoV-2 vaccination has disadvantages that should be considered before recommending it as a method of rapid mass vaccination

Sir,

We read with interest the article by Chandra et al¹. It was published in the March-April 2024 issue of the Indian Journal of Medical Research. A cross-sectional study on the incidence and characteristics of immediate adverse events following immunisation (AEFI) during a drive-through vaccination campaign for COVID-19 in Yogyakarta using the Sinovac/CoronaVac vaccine¹. Using secondary data from the local vaccine registry collected between July 27 and September 6, 2021, it was found that only 79 of 20817 vaccinated individuals had AEFI¹. Systemic adverse events were found to be more common than local events, including dizziness, nausea, fatigue, injection pain, palpitations, abdominal pain, anxiety, shortness of breath, vomiting, injection site itching, and fainting being the most common¹. The study is elegant, but some ambiguities should be clarified.

The first point is that only patients with diabetes, hypertension, cancer, or asthma were excluded according to the methods section¹. However, it is known that adverse reactions to SARS-CoV-2 vaccination (SC2V) occur more frequently in multimorbid patients than in previously healthy subjects or patients with an unspectacular medical history². Immunological diseases, in particular, are known to be associated with an increased risk of adverse reactions to SC2V³.

The second point is that in a drive-through setting, the time for a detailed and thorough medical history is too short, which is why a number of important information about the vaccine’s previous health status may have been overlooked. Since it was known from the beginning that the vaccines on the market were unsafe for certain patients⁴, it is irresponsible to allow such a setting without having the possibility to exclude patients at risk of SC2V side effects.

The third point is that some vaccines can cause not only mild but also severe side effects⁵. Therefore, we should know how many of the vaccinated had to be hospitalised due to severe side effects of the vaccination. The reasons for hospitalisation were also not explicitly stated.

The fourth point is that only the short-term side effects were recorded, not the long-term effects. Since SC2V can affect the immune system for months or possibly even for life, it would have been imperative to also record how many of the included patients still had vaccine-related side effects after one or two years.

As a fifth point, we disagree with the view that vaccination coverage is safe because only a few side effects occurred immediately after vaccination¹. Since several studies have shown that adverse reactions to vaccination can occur after a delay of days or weeks, which is due to delayed hypersensitivity reactions⁶, the evaluation of the safety profile of SC2V requires long-term monitoring.

In summary, drive-through vaccination against SARS-CoV-2 has several disadvantages that should be considered before making a general recommendation.