Booster shots for people with waning immunity after receiving initial vaccines could serve to significantly recharge a person’s resistance to Covid-19, according to new research.
The results of a Californian study, which has not yet been independently peer-reviewed, suggest that a person whose level of immunity may have fallen from 80% to 60% eight months after receiving the Pfizer vaccine can have their level of protection increased to 87% by way of a booster shot.
The research, which was conducted at the department of ecology at the University of California, measured levels of Covid resistance at several time points between one month after a second Pfizer or Moderna dose, eight months after the second dose, and one month after a third dose.
“The benefit of a third dose in reducing transmission is sizeable and increases with vaccine coverage,” it concludes, though with the caveat that “vaccination of unvaccinated individuals, especially in developing countries, would be more effective for reducing disease than providing a third dose to vaccinated individuals”.
Many countries have already begun booster shot campaigns, including Ireland which has thus far approved third doses for all people aged over 60, those in nursing homes, and those with compromised immune systems.
Ireland’s lead for the vaccination rollout, Professor Brian McCraith, declared the study’s findings to be “potentially very significant”, but noted that the research had yet to be independently evaluated.
Separately, a new study published insuggests that a common antidepressant could be used to reduce the effects of Covid among high-risk patients.
The randomised study involving the drug fluvoxamine, the largest piece of research conducted so far on the drug as a Covid-19 treatment, saw just 79 Brazilian adults out of 741 who were treated with the fluvoxamine require extended treatment or hospitalisation, compared with 119 out of 756 people who were treated with a placebo.
The study’s overarching aim was to identify inexpensive and widely available drugs to aid in the treatment of the coronavirus in countries of low resources and with limited access to vaccines.
Fluvoxamine, a drug ordinarily used to treat mental health conditions such as depression and obsessive-compulsive disorders, was chosen by the researchers due to its properties as an anti-inflammatory.
“Identifying inexpensive, widely available, and effective therapies against Covid-19 is of great importance, and repurposing existing medications that are widely available and have well-understood safety profiles is of particular interest,” said Edward Mills of McMaster University in Ontario, Canada, the co-principal investigator on the trial.
Meanwhile, Ireland has finished at the top of Bloomberg’s Covid resilience ranking index for the second month in a row, an indicator of how well economies are adjusting to a reopening with levels of the virus high across the planet.
Key to that ranking is the Irish level of vaccination, which at 74% for the population as a whole ranks highly among developed nations.
Other factors influencing the ranking include the ongoing severity of lockdown restrictions and a country’s access to reopened international travel routes.