NEW DELHI : More data is needed to establish if a third anti-COVID-19 booster dose will be more effective in fighting the surge of infections in the country as at present the recommendation is based more on conjecture, health experts said.India is battling a massive surge in COVID-19 cases and health ministry data updated on Sunday showed that a record single-day rise of 2,61,500 coronavirus infections has taken the country's total tally to 1,47,88,109, while active cases have surpassed the 18-lakh mark.Pfizer and Moderna recently announced that people who have received both doses of the Pfizer-BioNTech or Moderna coronavirus vaccines will probably need a booster shot this year and might need an annual shot thereafter.Earlier this month, an.