“Based on what we know now, the most likely scenario is that the COVID-19 virus continues to evolve, but the severity of the disease it causes decreases over time as immunity increases due to vaccination and infection,” said the general manager. Tedros Adhanom Ghebreyesus. Wednesday update. However, the WHO chief warned that periodic peak cases and deaths could occur as the immune system weakens, which may require periodic reinforcement for vulnerable populations. Speaking of the other two possible scenarios, Tedros said either less serious variants will appear and no boosters or new vaccines will be needed, or a more infectious variant will appear and protection against previous vaccination or infection will weaken quickly. The updated Strategic Plan for Preparedness, Preparedness and Response sets out the strategic adjustments each country needs to make to address SARS-CoV-2 transmitters, reduce the impact of COVID-19, and end the global emergency. This is the third Strategic Plan for Preparedness, Preparedness and Response released by the WHO and will probably be his last, Tedros said. The first report was released in February 2020, at the beginning of the pandemic.