The Centers for Disease Control and Prevention (CDC) confirmed what Harvard-affiliated researchers had reported based on anecdotal and laboratory findings: the delta variant of COVID-19 do not only spreads faster than other variants of the virus but, it can also infect vaccinated individuals, who can then spread the virus to others, Harvard News & Research reported.
The CDC revealed in its Morbidity and Mortality Weekly Report that 75 percent of patients in a cluster of 469 cases in Provincetown, Massachusetts, were vaccinated, a dismal statistic for Americans who were only weeks ago hopeful that the pandemic was coming to a conclusion. CDC Director Rochelle Walensky said in a briefing last Wednesday that new scientific evidence proves than delta behaves differently that other variants. Some vaccinated people may become contagious and spread the virus to others on rare occasions, she added.
Mark Poznansky, head of the Vaccine and Immunotherapy Center at Massachusetts General Hospital, has witnessed firsthand the circumstances Walensky described, including breakthrough cases of COVID-19 in vaccinated people. Poznansky said many of these patients dismiss early symptoms as a cold or other minor condition. Over time, people get tested and seek treatment, but they may have been spreading the infection as they went about their lives.
Delta Variant is Twice as Infectious
The CDC reported last week that the delta variation was found in 80% of samples nationwide. According to Jacob Lemieux, an infectious disease expert at Mass General and an instructor in medicine from Harvard Medical School, the recent spike in cases in Massachusetts has been almost entirely Delta.
The current infection rate in the US exceeds the pandemic’s first April 2020 spike. The seven-day average of new US cases had nearly doubled since June, reaching 66,000 on July 28. The seven-day average of deaths has grown from 100 to 200 in early July to roughly 400 late in the month.
During the winter, Delta infected millions in India. The new variant, considered to be approximately twice as contagious as the original, spread quickly, skyrocketing cases and deaths worldwide. Delta’s surge echoed global scientists’ concerns that leaving millions unvaccinated increases the risk of more transmissible — and potentially fatal — variations spreading even to vaccinated nations.
Vaccination is the Prime Method To Fight the Pandemic
Despite the threat posed by breakthrough infections, Walensky and Harvard infectious disease experts were clear that transmission still predominantly occurs among the unvaccinated and that vaccination is the No. 1 approach to fight the outbreak. In addition, whereas the delta variation has darkened the pandemic landscape, a bright spot is that the vaccines appear to preserve their capacity to protect against serious disease and death. That protection, experts added, appears to be true even for the elderly.