Moderna Inc. said it has made the initial batch of doses of a new Covid-19 vaccine designed to better protect people against a new strain of the coronavirus that has shown some resistance to the company’s original vaccine.
The Cambridge, Mass., company on Wednesday said it shipped the new shots to the National Institutes of Health to conduct the first human study of the variant vaccine, which could start within weeks.
The new vaccine, code-named mRNA-1273.351, is designed to better match the virus variant that was first identified in South Africa but has since spread elsewhere.
Moderna, which makes the second Covid-19 shot authorized in the U.S., might be the first vaccine maker to have finished the laboratory work of designing a shot targeting variants that started spreading swiftly late last year.
During the months preceding the surge of SARS-CoV-2 infections this fall and winter, many public health officials expressed concern about the potential for a “double-barreled” respiratory virus season. In this scenario, healthcare facilities would be totally overwhelmed by: 1) patients afflicted by infections caused by endemic respiratory viruses (such as influenza) that occur during any normal year, and 2) a massive influx of coronavirus patients. Fortunately, such a catastrophe did not come to pass. The reason for this is an unprecedented reduction in flu prevalence for the 2020–21 season.
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So perhaps a biological process, whereby viruses engage in some form of competition, or interactions, can better explain disappearances such as those currently being observed.
Subsequent research has borne out real world examples related to the phenomenon described by Simpson. According to a group of researchers at Yale, it is likely that a 2009 autumn rhinovirus epidemic interrupted the spread of influenza. The authors of that study write: “one respiratory virus can block infection with another through stimulation of antiviral defenses in the airway mucosa”. Results from another study, conducted in mice, support those findings. Mice were infected with either a rhinovirus or a murine coronavirus, and it was found that both attenuated influenza disease. Moreover, it was observed that the murine coronavirus infection reduced early replication of the influenza virus. In another study, negative interactions between noninfluenza and influenza viruses were suggested. According to the authors: “when multiple pathogens cocirculate this can lead to competitive or cooperative forms of pathogen–pathogen interactions. It is believed that such interactions occur among cold and flu viruses”. A recently published study examining the effects of interactions between an adenovirus and influenza in mice suggested that certain respiratory infections could impede “other viruses’ activities within the respiratory tract without attacking unrelated viruses directly”. Finally, in a paper entitled “A systematic approach to virus–virus interactions”, the authors state: “increasing evidence suggests that virus–virus interactions are common and may be critical to understanding viral pathogenesis”.
Federal flu maps use a traffic-light color scheme — green when flu is low, yellow when it’s medium and red when it’s high. Here in Massachusetts and around the country, the maps would normally show plenty of yellow and red by February. But this year they’re pure green.
And it’s not just flu that’s low. Dr. Eileen Costello, the chief of ambulatory pediatrics at Boston Medical Center, says it’s other viruses as well.
“We have seen dramatically reduced rates of influenza this year and respiratory synctitial virus, which is a viral infection of infants and very young children that we see,” she says. “It’s the meat and potatoes of every pediatric practice in America, and we’re not seeing it at all this year.
