International Journal of Preventive Medicine

: 2023  |  Volume : 14  |  Issue : 1  |  Page : 58-

COVID-19 brand switching: Expectation on protective efficacy

Beuy Joob1, Viroj Wiwanitkit2,  
1 Private Academic Consultant, Bangkok, Thailand
2 Honoary Professor, Dr DY Patil, University, Pune, Maharashtra, India

Correspondence Address:
Beuy Joob
Private Academic Consultant, Bangkok, 103300

How to cite this article:
Joob B, Wiwanitkit V. COVID-19 brand switching: Expectation on protective efficacy.Int J Prev Med 2023;14:58-58

How to cite this URL:
Joob B, Wiwanitkit V. COVID-19 brand switching: Expectation on protective efficacy. Int J Prev Med [serial online] 2023 [cited 2023 Oct 3 ];14:58-58
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Full Text

Dear Editor,

The new available coronavirus disesae COVID-19 vaccine becomes the new hope for the control of the disease. A recent report showed that the vaccine could induce protection in a large group of vaccinated subjects.[1] With the rapidly increasing demand for the COVID-19 vaccine, the supply is usually insufficient and the price of the vaccines becomes greatly different among different buyers.[2] At present, there are many brands of the COVID-19 vaccine with different cost-effectiveness properties.[3] Sometimes, it takes a long time to get a sufficient amount of COVID-19 vaccine supplied by a manufacturer. There is a new idea for vaccine brand mixing—different vaccine brands in different doses. As noted by Public Health England, this should be on extremely rare occasions.[4] To date, there are no data from the trial on the newly proposed ideas. However, it might be roughly predicted using a medical mathematical prediction. Here, the authors focus on the three different available vaccines for the switching model.

A basic assumption is that different vaccines are produced from different biotechnologies and have different basic components and immunogeneration mechanisms. The effect of switching the brand might be modeled based on the basic information on protective efficacy induced by the first dose of each vaccine. After the first dose, the protective efficacy is assumed to be according to the reported rate of each vaccine. After the second dose, the efficacy will be equal to the background protective efficacy from the first dosage plus additional protection from the second dose. The additional protection from the second dose by the switched second brand vaccine will be estimated by “the reported protective efficacy of the second switched brand vaccine if it is used as the first dose—the already derived protective efficacy of the first brand vaccine before switching.”

According to the switch modeling, the results are shown in [Table 1]. It can show that the expected effect of switching is various— either increasing or decreasing protective efficacy. This confirms the fact that it still requires further studies to evaluate the effect of switching. In case there is a lack of clinical data, the switching of vaccine brand should not be considered if it is not necessary.{Table 1}

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1Mallapaty S. Vaccines are curbing COVID: Data from Israel show drop in infections. Nature 2021;590:197.
2Dyer O. Covid-19: Countries are learning what others paid for vaccines. BMJ 2021;372:n281.
3Sookaromdee P, Wiwanitkit V. New COVID-19 vaccines, its cost and shelf life: A cost effectiveness analysis. Arch Med Res 2021;52:453.
4Mahase E. Covid-19: Vaccine brands can be mixed in “extremely rare occasions,” says Public Health England. BMJ 2021;372:n12