One of the problems with this COVID-19 pandemic, from a public health standpoint, is that asymptomatic or presymptomatic persons can transmit the virus to others without knowing that they are infected themselves. Estimates of asymptomatic transmission are 17-20%.
Protection procedure include isolation (keeping infected persons away from
others); and quarantine ( keeping persons who might have been exposed to the
virus away from others).
Asymptomatic infections complicate these
protective measures since it is impossible to tell who is infected. Current
practice is essentially to assume that anyone might be infected and capable of
transmission, and therefore masks and social distancing are necessary. Despite
trials showing 95% efficacy of the two mRNA vaccines (compared to 70%, possibly
higher, for the Johnson and Johnson vaccine), vaccination is not expected to
relax the recommendations for continued masks and social distancing. The
reasons are:
- Vaccines are not 100% effective;
- Vaccines protective effect is not maximized for at least six weeks;
- Vaccines may keep a person from getting sick but not from transmitting the virus.
Masks (if clean and properly worn) reduce
the spread of any mutated strain of the coronavirus, while vaccines may not be
as effective in preventing the transmission of newer, more contagious (but not
more virulent) strains. There have been several mutated strains appearing in
the UK, Brazil, South Africa, California, and other countries and states. As a
rule they do not cause a more severe case of the disease but they may be more
infective than existing strains.
Based on Dr. Glen Reeves article.
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