The news comes just in time for the 2020-2021 flu season, which is likely to coincide with a fresh resurgence of Covid-19 infections in countries this fall and winter. The confluence of these two viruses could overwhelm already strained medical resources and complicate testing procedures, particularly given the diseases that lead to remarkably similar symptoms.
A previous study, published in the Lancet in June, had shown that a single dose of baloxavir was as effective as Tamiflu (oseltamivir) in reducing the duration of the flu when given twice a day for five days. But the new July study is perhaps even more significant, as it shows the role baloxavir plays in reducing the spread of the disease among family members.
We have all become aware of the ease with which respiratory infections can spread within families and in schools, dormitories or other places where people gather together for long periods of time. A prophylactic drug with the potential to significantly reduce the incidence of pandemic influenza is indeed very welcome news.
8, baloxavir was initially approved for the treatment of simple influenza A and B in Japan and for the treatment of people 12 years of age and older in the United States. The July study was conducted during the 2018-2019 flu season in Japan and assessed baloxavir’s ability to reduce transmission within a family. In most cases, the first family member to get the flu was an 11 year old or younger. In particular, family members were not vaccinated for the flu. Upon detection of an influenza infection in at least one family member – judged by both fever, at least one moderate or worse respiratory symptom, and a positive flu test – uninfected family members were given a placebo or baloxavir.
In families that received the placebo, 13.6% of residents contracted the flu. Only 1.9% of those who received baloxavir experienced the flu and no serious side effects were detected in the treatment group.
But there are many caveats. Two flu strains typically circulate in the autumn and winter months, influenza A and B. Although baloxavir is approved for use against both influenza A and B, influenza B was not active in Japan during the season flu 2018-2019. The hope, although not demonstrated in this study, is that the drug will also protect against B flu infections.
Family transmission that begins with a child is one of the most frequent ways of passing on flu, although it is by no means the only one. The virus can be transmitted in many different contexts including colleges, workplaces, sporting events, theaters and other social gatherings. The authors argue that home transmission prevention supports the idea that the prophylactic use of baloxavir will also reduce transmission in other settings.
Baloxavir works with a new mechanism. The flu virus uses a process called cap snatching to reproduce itself, ripping off parts of a host cell’s RNA and using it to continue the reproduction process. Baloxavir binds and inhibits the protein the virus needs to reproduce. Human cells lack any enzyme or similar function.
Baloxavir’s success against flu transmission is significant and provides hope that drugs directed against other viral enzymes can be developed for the treatment and prevention of Covid-19.
In critical condition, many health systems are found today – with hospitals and suppliers already overwhelmed after months of treatment for Covid-19 infections – an approved drug that could help reduce the number of people who get flu this winter will be a welcome relief. . Effective Covid-19 antiviral drugs for prophylactic treatment are unlikely to be available for most of those at risk of Covid-19 by autumn and winter. Likewise, a safe and effective vaccine may also not be widely available.
A combination of a seasonal flu vaccine and an effective prophylactic drug like a baloxavir – in addition to the personal protective behaviors already practiced in the United States – could significantly reduce the severity of the future flu epidemic and save our hospitals the worst of the combined effects. of simultaneous epidemics.