Answer to Paredes et al. commenting on "COVID-19 vaccines under the International Health Regulations — We must use the WHO International Certificate of Vaccination or Prophylaxis". (April 2021) - Petersen, Eskild; Lucey, Daniel; Blumberg, Lucille; Kramer, Laura D.; Al-Abri, Seif; Lee, Shui Shan; Pinto, Tatiana de Castro Abreu; Obiero, Christina W.; Rodriguez-Morales, Alfonso J.; Yapi, Richard; Abubakar, Aisha; Tambyah, Paul Anantharajah; et al.