Reference
1. Wang C, Wang Z, Wang G, Lau JY-N, Zhang K, Li W. COVID-19 in early
2021: current status and looking forward. Signal Transduction and
Targeted Therapy 2021; 6 (1): 1-14.
2. Chookajorn T, Kochakarn T, Wilasang C, Kotanan N, Modchang C.
Southeast Asia is an emerging hotspot for COVID-19. Nature
Medicine 2021: 1-2.
3. Vassallo M, Manni S, Klotz C, et al. Patients admitted for variant
alpha COVID-19 have poorer outcomes than those infected with the old
strain. Journal of clinical medicine 2021; 10 (16): 3550.
4. Farinholt T, Doddapaneni H, Qin X, et al. Transmission event of
SARS-CoV-2 Delta variant reveals multiple vaccine breakthrough
infections. BMC medicine 2021; 19 (1): 1-6.
5. Liu Y, Gayle AA, Wilder-Smith A, Rocklöv J. The reproductive number
of COVID-19 is higher compared to SARS coronavirus. Journal of
travel medicine 2020.
6. Ghosh N, Saha I, Sarkar JP, Maulik U. Strategies for COVID-19
Epidemiological Surveillance in India: Overall Policies Till June 2021.Frontiers in Public Health 2021; 9 .
7. Shrivastava S, Mhaske ST, Modak MS, et al. Emergence of Two Distinct
Variants of SARS-CoV-2 and Explosive Second Wave of COVID-19: An
Experience From A Tertiary Care Hospital, Pune, India. 2021.
8. Reardon S. How the Delta variant achieves its ultrafast spread.Nature 2021; 21 .
9. Cevik M, Grubaugh ND, Iwasaki A, Openshaw P. COVID-19 vaccines:
Keeping pace with SARS-CoV-2 variants. Cell 2021.