There is growing optimism and hope that due to ongoing immunization efforts seasonality (declining infections through August) and naturally acquired immunity, the number of deaths and hospitalizations related to COVID-19 in the United States will be significantly reduced by spring and early summer 2021. Several crucial elements, however, must temper this optimism. The chances of attaining herd immunity against SARS-CoV-2 are slim because not everyone in the United States is eligible to be vaccinated. A quarter of those who are will likely refuse to be vaccinated. Furthermore, the vaccines do not provide complete protection against infection, and the existing vaccines are ineffective against variant B.1.351 and possibly other variants. As a result, the public and health systems must work together. The demand for family health insurance plans has increased over time.
Herd immunity is a theoretical concept in infectious disease modelling those states, “In a population where everyone is equally likely to encounter everyone else, the transmission will stop when immunity from the previous infection, vaccination, or both reaches 1 (1/R), where R is the number of infections caused by a single infection in a population where everyone is susceptible”. Reality deviates from this straightforward notion. First, because COVID-19, like other coronaviruses, is seasonal, herd immunity will be lower in the summer and higher in the winter.
Second, herd immunity is dependent on the amount of interaction that individuals have with one another, which will vary by state or city once social distance rules are removed.
Third, non-random mixing (where individuals are not equally likely to interact with one another) can alter the degree of immunity needed to prevent transmission. Despite these variables, some public health professionals believe that achieving winter herd immunity in the face of new, more contagious variations will necessitate the immunization of more than 70% to 80% of the population. It would be best to understand the benefits of a critical illness plan.
Final thoughts
Obtaining herd immunity to COVID-19 will be difficult due to three important considerations. Initially, vaccinations will have lower effectiveness in preventing infection from the B.1.351 strain for wild-type variations like Moderna and Pfizer vaccines have a 95 percent overall efficacy against symptomatic disease. Adenovirus vector vaccines, such as the Janssen/Johnson & Johnson vaccine, have overall effectiveness of 70%. However, the only evidence on vaccination efficacy for infection prevention comes from a single group in the AstraZeneca trial, which demonstrated 55% protection against infection as measured by weekly nasal swabs vs. 70% protection for symptomatic disease.
Various models imply that COVID-19 surges could continue even if B.1.351 supremacy is lost. A winter increase in infection with B.1.351 dominance is possible in 2021–2022. On the other hand, hospitalization and death rates may reduce if vaccinations continue to be increasingly successful in reducing symptomatic sickness and severe disease and death. For example, even in South Africa, the Janssen vaccine was more than 85% effective against severe illness, with no hospitalizations or fatalities reported in the trial, albeit with an extensive confidence interval for these outcomes.
