Strategies and safety considerations of booster vaccination in COVID-19

Abstract

First-generation SARS-CoV-2 vaccines have played a significant role in controlling the COVID-19 pandemic, preventing severe diseases, and reducing mortality. However, the continuous emergence of SARS-CoV-2 variants, the persistence of breakthrough infections, and the seemingly rapid decline in the protective efficacy of SARS-CoV-2 vaccines have presented additional challenges for the next phase. There is an urgent need to confirm the necessity of further booster vaccination and combination vaccine approaches. This paper summarizes the latest literature on SARS-CoV-2 variants and vaccine effectiveness and concludes that it is essential to implement booster immunization strategies. Priority should be given to high-risk groups, the elderly, and immunocompromised people. In addition, heterologous vaccination has a longer duration of effect and a broader spectrum than homologous vaccination, making it more conducive to managing the immune escape of SARS-CoV-2 variants.

Booster Doses of Anti COVID-19 Vaccines: An Overview of Implementation Policies among OECD and EU Countries

“…However, the best strategies and dosing intervals to provide maximum benefit, especially in the context of the new variants spread, still need to be clearly defined [ 63 ]. Similarly, although many policies define priority groups to administer vaccines as reported in our results, a systematic review concluded that the current evidence on prioritization is still insufficient and there is need of adequately powered research assessing this issue [ 65 , 66 ].…”

Nonpharmaceutical interventions for COVID‐19 disrupt the dynamic balance between influenza A virus and human immunity

“…Severe acute respiratory syndrome coronavirus 2 is a severe infectious respiratory virus that causes COVID‐19 and damages almost all human organs, including the lungs, heart, kidneys, liver, and brain, even leading to death in severe cases. 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 To contain the sudden COVID‐19 epidemic, almost all countries in the world have not only recommended that their citizens be vaccinated against COVID‐19 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 but also adopted a series of strict NPIs, such as hand hygiene, use of face masks, social distance, limiting mass gatherings, school closures, and staying at home orders. NPIs disrupt the transmission chain of respiratory diseases, so they are equally effective in controlling other respiratory virus infections.…”

Development of inhaled COVID-19 vaccine and its benefits

“…As the experiment showed, a booster dose of vaccine can increase the titer of neutralizing antibodies. "The results showed that the neutralizing antibody titers increased from 440AU/mL to 25,468 AU/mL after the booster dose, and no serious adverse events were reported during this period" [4].…”

“…Homologous inoculation refers to injecting the same type of vaccine as a booster. In contrast, heterologous vaccination refers to a "combination of vaccines from different manufacturers or different techniques routes" [4]. Homologous inoculation, injecting the same vaccine and triggering the second immune response, elicit rapid and intense secretion and maturity of antibodies, resulting in longer protection effectiveness.…”