Vaccination alone may not be enough to end the pandemic. To reveal this scenario are two scientific studies just published by Science e The Lancet which come from Georgetown University Medical Center in Washington and the University of Warwick, UK, respectively. According to American researchers, protection against the spread of the asymptomatic form of Covid-19 will be the only key to ending the restrictions. “Contagious people with no observable signs of disease render infection prevention efforts with face masks, social distancing, hand hygiene and symptom screening useless. We cannot therefore rely on vaccination alone to control the pandemic: vaccines are great for protecting people from disease, but we still don’t know how well they work to protect us from transmission “, says the virologist. Angela Rasmussen “Until there is solid surveillance and epidemiological measures that will allow us to put out these smokeless fires – that is, the spread of asymptomatic cases -, the pandemic cannot be completely extinguished.”
The interview
Covid free summer. The mayor of Lampedusa: “Full vaccinations, We will be the first virus-free island”
by Elvira Naselli
The American study, published in Science demonstrates that symptom-free transmission silently drives viral spread and is based on the concept that “vaccines do not offer one hundred percent protection against getting sick and are not even a hundred percent likely to protect against transmission,” in addition to the fact that the virus travels freely around the world and the vaccination campaign is not homogeneous, just like the availability of vaccines. “Asymptomatic and presymptomatic transmission represent a unique public health challenge,” adds the co-author Saskia Popescu. “Ultimately, it will be something we will have to keep an eye on continuously as we move on to the next phase of the pandemic and the reduction of disease due to vaccinations.”
Covid, what can be done after two doses of the vaccine according to the Americans
by Irma D’Aria
The British researchers share the same opinion, according to which “vaccination alone is unlikely to contain infections, leading to herd immunity. Therefore, the gradual release of control measures, a high uptake of the vaccine and a vaccine with a high protection against infections will be essential to minimize future waves “, says the epidemiologist. Matt Keeling. The analysis carried out by researchers at the University of Warwick is based on the first data available since the introduction of the vaccine in the world. “Preliminary results suggest that the vaccine offers a level of protection against infection, but the exact level is still unclear, regardless of the emergence of new variants, for which the vaccine may offer less protection. We also found that the sudden and early release of restrictions is likely to lead to a major wave of infection, while the gradual easing of measures over a period of many months could reduce the peak of future waves, “adds Keeling.” Some measures, such as testing, tracking and isolation, good hand hygiene, use of masks in high-risk environments and tracking of super-shedding events may be needed for some time yet. “
Longform
Covid vaccine: the Italian anomaly of adverse reactions
by Giuseppe del Bello
Projections, from January 2021 to January 2024, assume that although vaccination can substantially reduce RT, it may not be enough to bring it below 1. In the most optimistic scenario, i.e. with 85% vaccine protection, without further restrictions, the Rt number would be around 1.58. “Since vaccination alone is not expected to bring RT below 1, removing all restrictions would lead to another wave of infections with a substantial number of deaths. The extent of future waves and the number of deaths are influenced by how early the measures will be relaxed, the level of protection of the vaccine against infections and the intake of the vaccine. Even small loosening, if done abruptly, is expected to lead to large waves of infection. “
“We are rapidly learning more about the effectiveness of vaccines as vaccination programs are rolled out around the world – adds the co-author. Sam Moore -. Since we conducted this study, new evidence suggests that there may be a higher level of protection against serious diseases offered by Pfizer and AstraZeneca vaccines than the level we have assumed. This could reduce the size of future hospital admissions and estimated deaths, making future waves more manageable for the health service. Regarding protection against infections, some preliminary results have suggested that the vaccine offers a level of protection against infection, but the exact level of protection offered by vaccines is still unclear. We will continue to update our predictions as new vaccine efficacy data becomes available. “
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