The Advisory committee for vaccines and immunization practices (ACVIP) recommendations of 2018-19 are a mix of best practices for individual children, and for community use, based on published studies, World Health Organization (WHO) recommendations, and National immunization program.

Author cites the Centre for Disease Control (CDC), USA recommendation that the fourth dose of Hepatitis B vaccine should not be administered before 24 weeks whereas WHO recommends birth dose (using monovalent vaccine) to all infants followed by 2 or 3 additional doses (monovalent or combined vaccines) to complete the primary series with minimum 4 weeks’ interval between doses [1]. CDC recommends primary vaccination at 2,4,6 months whereas WHO recommends primary vaccination at 6,10,14 weeks and the ACVIP recommends the latter. Indian studies using different schedules as 0,6,14 weeks and 0,1,2 months [2] and 6,10,14 weeks [3,4] have also reported adequate immunogenicity. All the 3-dose hepatitis schedules protect from the disease for as long as 15-20 years. Even if protective antibody titers decline with time, long-term protection relies on immunological memory that allows a protective anamnestic response after exposure to Hepatitis-B virus.　

The effectiveness of licensed acellular pertussis (aP) and whole cell pertussis (wP) vaccines in preventing disease is similar in the first year of life [5], and hence the committee accorded near equal status to both types of the vaccines [6]. Clinical phase III studies in India demonstrated that the aP containing vaccines elicit a robust immune response in Indian children following a primary immunization schedule at 6, 10 and 14 weeks of age [7,8].

In view of limited manufacturing capacity for IPV, WHO has supported fractional IPV (fIPV) use and hence government has adopted the same. ACVIP recommends administration of full dose of IPV at 6,10,14 weeks as preferred option, and when this is not feasible the fIPV at 6 and 14 weeks along with bOPV at 6,10,14 weeks.

Reasons for introduction of influenza vaccine have been clearly detailed in the ACVIP recommendations [9].

As Measles-Rubella (MR) vaccine has been introduced in the national immunization schedule and in MR campaign, the same was mentioned. ACVIP supports the national MR campaign. We have not changed the earlier recommendations at all on Measles Mumps Rubella (MMR) vaccine.

Regarding TCV, the committee has brought down the age for the vaccination based on adequate immunogenicity data from earlier studies. The recommendation from 6 months onwards is to suit the convenience and avoid overcrowding of vaccinations around 9 months. The need for second dose of TCV has not been convincingly established though most studies indicate that a single dose might provide adequate antibody titres for up to 5 years. Until hard data is generated or available, we have endorsed the WHO recommendation of a single dose as of now. Antibody titres have been reported to be sufficient for 30 months after one dose and enough data is not there as of now to justify a booster at 2 years. It should be noted that no international scientific body has endorsed booster doses.

Infants in developing countries are at risk of developing rotavirus gastroenteritis at an earlier age than those in developed countries. Hence, it is ideal if immunization schedule is completed early. A recent meta-analysis [10] showed that 6,10 weeks’ schedule for rotavirus 1 (RV1) is immunologically inferior to 10,14 weeks’ schedule. However, the authors mentioned that the correlates of protection of anti-rotavirus IgA levels are not known and "the association between vaccine schedule and immunogenicity does not provide evidence of a difference in disease protection" [9]. The upper age limit of 12 months follows the same in National immunization schedule which recommends beginning of RV immunization up to 1 year of age. This age limit is for catch-up immunization.　

1. World Health Organization. WHO Recommendations for Routine Immunization - Summary Tables, Table I. Available from: https://www.who.int/immunization/policy/Immuni-zation_routine_table1.pdf?ua=1. Accessed March 15, 2019.

2. Mittal SK, Rao S, Kumar S, Aggarwal V, Prakash C, Thiruparam S. Simultaneous administration of hepatitis B vaccine with other EPI vaccines. Indian J Pediatr. 1994;61:183-8.

3. Kumar TS, Abraham P, Raghuraman S, Cherian T. Immunogenicity of indigenous recombinant hepatitis B vaccine in infants following 0, 1, 2 month vaccination schedule. Indian Pediatr. 2000;37:75-80.　

4. Gomber S, Sharma R, Ramchandran VG, Talwar V, Sinha B. Immunogenicity of Hepatitis B vaccine incorporated into Expanded Program of Immunization Schedule. Indian Pediatr. 2000;37:411.

5. Pertussis vaccines: WHO position paper – August 2015. Weekly Epidemiological Record. No. 35. 2015;90:433-60.

6. Witt MA, Arias L, Katz PH, Truong ET, Witt DJ. Reduced risk of pertussis among persons ever vaccinated with whole cell pertussis vaccine compared to recipients of acellular pertussis vaccines in a large US cohort. Clin Infect Dis. 2013;56:1248-54.

7. Chhatwal J, Lalwani S, Vidor E. Immunogenicity and safety of a liquid hexavalent vaccine in Indian infants. Indian Pediatr. 2017;54:15-20.　

8. Lalwani SK, Agarkhedkar S, Sundaram B, Mahantashetti NS, Malshe N, Agarkhedkar S, et al. Immunogenicity and safety of 3-dose primary vaccination with combined DTPa-HBV-IPV/Hib in Indian infants. Hum Vaccin Immunother. 2017;13:120-7.

9. Balasubramanian S, Shah A, Pemde HK, Chatterjee P, Shivananda S, Guduru VK, et al. Indian Academy of Pediatrics (IAP) Advisory Committee on Vaccines and Immunization Practices (ACVIP) Recommended Immunization Schedule (2018-19) and Update on Immunization for Children Aged 0 Through 18 Years. Indian Pediatr. 2018;55:1066-74.