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Indian Journal of Community Medicine

Knowledge and Practice of Oral Polio Vaccine-Vaccine Vial Monitor Among Health Personnel in India

Author(s): Kamlesh Joshi, JS Thakur, Amarjeet Singh

Vol. 32, No. 4 (2007-10 - 2007-12)

ISSN No. 0970-0218

Kamlesh Joshi, JS Thakur, Amarjeet Singh

Vaccine vial monitor (VVM) is a valuable logistic management tool for indicating vaccine potency. It is present on all oral polio vaccine (OPV) vials supplied by UNICEF since 1997. The VVM basically monitors the cumulative heat exposure of the vaccine vial and provides information only about that vials to which it is attached.1 The availability of VVMs on OPV has facilitated the implementation of the multi-dose vial policy by WHO, which allows opened vaccine vials to be used for more than 1 day. This has led to a dramatic reduction in the discard rate of the vaccine due to heat exposure and unused portion of opened vials by 45% and 77%, respectively.1 In addition, the VVM has been recognized with the advantage that it needs less-stringent cold chain at the field level, thus decreasing the burden of cold chain requirement.

Training on VVM has also been provided to the health personnel, regularly. However, a lot of confusion still prevails among them with regard to VVM. During a training session on immunization strengthening project (ISP) for district-level medical officers (MOs) at Community Medicine Department, Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh in September 2002. Most mid-level MOs were not clear about the facts related to VVM. VVM is likely to be included in near future for all other vaccines as well. It was, therefore, decided to carry out a study to assess the prevailing knowledge and practice regarding oral polio VVMs among health personnel in India.

Materials and Methods

A pre-tested semi-structured questionnaire was used for the study. It was proposed to interview a minimum of 100 health personnel of different cadres. This included health personnel available in the field practice area of the departments, namely, pediatricians, neonatologists of PGIMER and MOs and senior MOs of six states, Union Territory (UT) of India viz, Haryana, Punjab, Chandigarh, Rajasthan, Bihar and Jharkhand, who participated in the ISP training course in the Department of Community Medicine, PGIMER, Chandigarh. No sampling was done. Respondents were selected purposively. The selection and interview of the respondents was done as per their availability. The study was conducted in the month of October and November 2002.

The questionnaire sought information pertaining to relevance of testing of VVM by health personnel and their knowledge and use of oral polio VVM. Any other comments made by the respondents were also noted. The responses given by the health personnel were entered into the computer. Details of respondents were recorded according to the category of health personnel, years in service and training received for VVM. Knowledge and use of VVM is presented as ‘yes’ and ‘correct’ responses. In some of the questions, the responses are presented in detail with all the options. Number along with percentage and no responses are computed and presented. Analysis was done using Epi-Info version 6.0.


A total of 115 health personnel were interviewed. More than half (55.6%) of them were block-level officers and below, 28.6% were district- and state-level officers, 6% were medical institution faculty/health trainers, 1.7% were health administrators and 7.8% were peripheral health staff. More than half of those interviewed (55.6%) had a service experience of 19 years or more, 25.2% had experience of 6 years or less and 19.1% had 7–18 years of service experience. Fifty-two percent had received immunization-related training twice or more, whereas 36.4% had received training at least once. Response to question on training received was not given by 11.3%.

Table 1 presents the knowledge about use of OPV-VVM among the respondents. Around 14% of health personnel supported the experiment of OPV-VVM by the doctors who kept OPV vials in sunlight or put the vials in boiling water. Testing of OPV-VVM color change was tried by 24.3% of respondents themselves. Majority tested it by keeping the vial outside the cold chain (68.2%), followed by keeping the vial in sunlight (18.2%) and by keeping the vial in pocket (6.8%). Some of the respondents reported that they tested VVM by direct heating of the vial. For 51.2% respondents, the testing was prompted by a failure of anticipated change in VVM color when they had evidence of breakdown of cold chin, whereas 26.8% did it just out of curiosity. Around 44% of respondents did not observe any color change in VVM when they tested it by exposing the vial to a higher temperature, 34.9% observed change in color to stage 3 or stage 4 and 20.9% observed color change to stage 2.

Table 1: Knowledge and use of oral polio vaccine-vaccine vial monitor among health personnel (N = 115)

Knowledge and used of oral polio vaccine-vaccine vial monitor Yes % No response
Some doctors have tried testing of oral polio VVM color by keeping the
OPV vials in sunlight or by putting the vials in boiling water. Do you
agree with the testing of oral polio VVM by these doctors?
16 13.9 3
Have you ever tried such testing of oral polio VVM color change? 28 24.3 0
During a house-to-house campaign on NID and mop-up rounds, some
HWs were found carrying OPV vials in their pockets. According
to you, were the HWs correct in doing so?
15 13.0 0
Once an OPV-VVM vial is exposed to sunlight and the VVM is within
stage 1 and stage 2, will you continue to use the vial?
64 55.7 1
Have you heard about the term ‘fast chain’? 14 12.6 5
Once an OPV vial with VVM is opened, how long will you continue to use it
For 1 day 42 36.5
For 2 days 1 0.9
Depending on status of VVM 71 61.7
For 3 day or more 1 0.9
In a particular batch of OPV vials if VVM of one vial has reached discard point
(stage 3 or stage 4), which of the following actions you would take?
Reject that vial only
22 19.5
Reject the whole batch of vials irrespective of VVM status 20 17.7
Will check the whole batch for VVM change and reject stage 3 or stage 4 vials only 61 54.0
Will reject only after ascertaining the potency of the vials reaching stage 3 and stage 4 10 8.8
No response 2 1.7
Which of the following indicate the main advantage of introduction of VVM
in immunization program
Convenience-No more need for HWs to carry bulky vaccine carriers 7 6.3
Flexibility-HWs can continue immunization for a longer time 30 27.0
Both of the above 29 26.1
None of the above 44 39.6
No response 5 4.3

HWs: Health workers, OPV-VVM – Oral polio vaccine-vaccine vial monitor

Thirteen percent of respondents endorsed the decision of health workers (HWs) who carried OPV vials in their pockets and administered the vaccine as long as the VVM has not changed its color. More than half (55.7%) of the respondents said that use of OPV-VVM vials should be continued even when exposed to sunlight if the VVM was still in stage 1 or stage 2. Only 12.4% knew about the time taken for OPV-VVM to reach discard point at 37°C continuous ambient temperature and only 12.6% were aware about the term ‘fast chain’.

Most of the respondents (61.7%) told that once an OPVVVM vial is opened, its use might be continued depending on status of opened-VVM vial, its use might be continued depending on status of VVM. Fifty-four percent opined that if in a particular batch of OPV-VVM when one vial has reached discard point, they will check all the OPV vials in that batch for VVM change and reject only stage 3 or stage 4 vials, whereas 17.7% advocated discarding the whole lot of vials even if one vial had VVM in stage 3 or stage 4. Forty percent of healthy personnel were not aware of the main advantage of introduction of VVM in immunization program i.e., flexibility and convenience.


During the ISP training course for district-level MOs at Community Medicine Department, PGIMER, Chandigarh, India in September 2002, the issue of VVM was hotly debated. The debate left us with the impression that a lot of confusion still prevails with regard to VVM among middle-level managers of immunization program in India. One can safely assume that much more confusion prevails lower down at the level of MOs and HWs. The various issues discussed during the debate were:

Were these doctors really wrong in experimenting with VVMs?

It appears that in consonance with the marketing strategy for launching a new product, WHO, in all its good sense, advocated testing of VVM by mid-level managers at their level apparently to familiarize them with it.2 The VVM fact sheet also states. “To gain confidence, EPI managers are encouraged to test VVMs in their own region.” Here also, the mid-level managers have found VVM wanting because it did not show the ‘expected’ change on exposure to heat/sunlight. Such expectations were due to lack of the concept among them that VVM reflects cumulative exposure to heat rather than one time exposure through boiling or keeping the vial in sunlight. However, the boiling aspect needs to be debated as it is expected to destroy the potency of the vaccine. In such case there is no use of VVM.

Some trainees observed that during house-to-house campaigns on NIDs and mop-up rounds, HWs carried OPV vials in their pockets.

Vaccine vial monitor has many advantages and which greatly depends on the quality of the cold chain condition from the level of production. For the success of goal of polio eradication, it is necessary that storage and transport of OPV be ensured at all levels. Slackening in the cold chain maintenance should not be allowed at any cost.

The question is, were these HWs wrong in carrying OPV vials in pockets? In our study, only 13% respondents endorsed it. The concept of ‘fast chain’, a cold chain strategy, that seeks to increase the effectiveness of campaigns by a reduction of the dependence on cold chain equipment at peripheral level through pro-active management and short supply lines could have been applied over here. As per this concept, OPV vials can be carried to the periphery even without icepacks and used as long as VVM is all right. However, the fact that majority of our respondents did not agree with the idea of carrying OPV in pockets, reflects that they were not convinced. Moreover, many of our respondents reflected that such overconfidence among health staff while using vials with VVM was also causing complacency in them. They tend to develop a casual attitude towards cold chain. Such complacency with regard to cold chain due to VVM is also likely to have a spill-over effect on to the other EPI vaccines, unless provided with a VVM. Similar apprehension was also raised by WHO that until VVM are available for all vaccines, there is a clear danger that vaccines with VVM will be used as a proxy for vaccines without VVM.

As VVM indicates the status of single vials of OPV at any given moment, is the lot quality technique of quality assessment valid for rejection of the whole lot of OPV vials with VVM? If yes, well it not increase vaccine wastage? But clearly, the senior health officials in our training course were not aware of this aspect. This also needs clarification that can we still rely on the sunlight exposed vaccine potency with VVM color unchanged? This issue needs further debate.

It is worthwhile to analyze why such a reaction is there for VVM among health personnel. Consequent upon experimentation by doctors many word of mouth stories are circulating. Such a scenario has created confusion in the minds of the health care delivery system (HCDS) officials. Similar reaction was highlighted by the VVM impact study in Turkey, which concluded that the current trend among the staff was to consider VVM as ‘defective’ because “it does not darken as fast as it should”.1

It is, therefore, imperative that apart from adequate supervision, further clarification/guidelines be supplied to the health staff; by WHO/UNICEF/Government of India, during training sessions in an unambiguous language regarding maintenance of cold chain for OPV and other vaccines relevance of experimentation with VVM and the potentials benefits of VVM so that the unnecessary confusion is removed.


  1. Asfar OZ. Altay B. Vaccine vial monitor impact study during 1997 National Immunization Days in Turkey. WHO/EPI/ TECHNET.98/WP.23
  2. Kotler P. Armstrong G. Principales of marketting’ 8th ed. New Jersey. Prentice-Hall Inc. 1999
  3. John TJ. Vaccine potency: A doctor’s dilemma. Indian Pediatr 2000;37:1023-4.

Department of Community Medicine, Postgraduate Institute of Medical Education and Research, Chandigarh, India

Correspondence to:
Dr Amarjeet Singh,
Department of Community Medicine, Postgraduate Institute of Medical Education and Research, Chandigarh – 160 012, India.
E-mail: amarminhas56(at)
Received: 22.03.06
Accepted: 13.09.06

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